<nz-dropdown [nzPlacement]="'bottomLeft'">
  <button nz-button nz-dropdown>bottomLeft</button>
  <ul nz-menu>
    <li nz-menu-item>
      <a>1st menu item length</a>
    </li>
    <li nz-menu-item>
      <a>2nd menu item length</a>
    </li>
    <li nz-menu-item>
      <a>3rd menu item length</a>
    </li>
  </ul>
</nz-dropdown>
<nz-dropdown [nzPlacement]="'bottomCenter'">
  <button nz-button nz-dropdown>bottomCenter</button>
  <ul nz-menu>
    <li nz-menu-item>
      <a>1st menu item length</a>
    </li>
    <li nz-menu-item>
      <a>2nd menu item length</a>
    </li>
    <li nz-menu-item>
      <a>3rd menu item length</a>
    </li>
  </ul>
</nz-dropdown>
<nz-dropdown [nzPlacement]="'bottomRight'">
  <button nz-button nz-dropdown>bottomRight</button>
  <ul nz-menu>
    <li nz-menu-item>
      <a>1st menu item length</a>
    </li>
    <li nz-menu-item>
      <a>2nd menu item length</a>
    </li>
    <li nz-menu-item>
      <a>3rd menu item length</a>
    </li>
  </ul>
</nz-dropdown>
<nz-dropdown [nzPlacement]="'topLeft'">
  <button nz-button nz-dropdown>topLeft</button>
  <ul nz-menu>
    <li nz-menu-item>
      <a>1st menu item length</a>
    </li>
    <li nz-menu-item>
      <a>2nd menu item length</a>
    </li>
    <li nz-menu-item>
      <a>3rd menu item length</a>
    </li>
  </ul>
</nz-dropdown>
<nz-dropdown [nzPlacement]="'topCenter'">
  <button nz-button nz-dropdown>topCenter</button>
  <ul nz-menu>
    <li nz-menu-item>
      <a>1st menu item length</a>
    </li>
    <li nz-menu-item>
      <a>2nd menu item length</a>
    </li>
    <li nz-menu-item>
      <a>3rd menu item length</a>
    </li>
  </ul>
</nz-dropdown>
